The LCROSS team took the known near-infrared light signature of water and compared it to the impact spectra LCROSS near-infrared recorded after the probe had sent its spent rocket crashing into the moon.

A spectrometer helps identify the composition of materials by examining which wavelengths of light they emit or absorb.

"We got good fits" for the data graphs, said Anthony Colaprete, LCROSS's principal investigator, at today's press conference at the NASA Ames Research Center in Moffett Field, California.

Additional support for moon water came from LCROSS's ultraviolet spectrometer, which detected energy signatures associated with hydroxyl, a byproduct of the breakup of water by sunlight.

The amount of lunar water kicked up by the LCROSS crashes could fill about a dozen 2-gallon (7.6-liter) buckets, said Colaprete, adding that this is just a conservative estimate.

"Not Your Father's Moon," Water Discovery Suggests

The confirmation of water on the moon raises the possibility that humans may one day be able to extract drinking water or breathable oxygen as well as the raw ingredients for rocket fuel from moon rocks, Michael Wargo, chief lunar scientist for Exploration Systems at NASA headquarters in Washington, D.C., said at the conference.

Water samples from the moon might also help shed light on the early history and evolution of the solar system, said physicist Greg Delory, a senior fellow at the Space Sciences Laboratory and Center for Integrative Planetary Sciences at the University of California, Berkeley.

"This is not your father's moon," Delory said at the conference.

"Rather than a dead and unchanging world, it could be a very dynamic and interesting one."